Oil pump system for vehicle

• US 20080286123A1
• Filed: 05/16/2008
• Published: 11/20/2008
• Est. Priority Date: 05/17/2007
• Status: Active Grant

• Current Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Original Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Inventors: Yoshinami, Koudi
• Granted Patent: US 8,403,646 B2
• Time in Patent Office: Days
• US Class Current: 417/118
• CPC Class Codes: F04C 14/02 specially adapted for several machines or pumps connected in series or in parallel
• CPC Class Codes: F04C 14/06 specially adapted for stopping, starting, idling or no-load operation
• CPC Class Codes: F04C 2/102 the two members rotating simultaneously around their respective axes
• CPC Class Codes: F04C 2/3446 the inner and outer member being in contact along more than one line or surface
• CPC Class Codes: F04C 2240/45 Hybrid prime mover
• CPC Class Codes: F16H 2312/14 Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights
• CPC Class Codes: F16H 61/0031 using auxiliary pumps, e.g. pump driven by a different power source than the engine

Abstract

An oil pump system for a vehicle includes: a vane pump having a plurality of vanes which respectively project retractably from a plurality of vane accommodating grooves provided in a rotor so as to be brought into sliding contact with a cam surface, the vane pump being adapted to supply a hydraulic fluid to an automatic transmission; an electric power-driven oil pump for assisting the hydraulic pressure of the hydraulic fluid during an idling stop of the automobile; and an ECU for controlling its operation. During an idling stop, the hydraulic fluid is fed to the automatic transmission by the operation of the electric power-driven oil pump to assist the hydraulic pressure, while the hydraulic fluid is fed with pressure also to the vane accommodating grooves to press the vanes against the cam surface.

Claims

1. An oil pump system for a vehicle comprising:

a vane pump having a plurality of vanes which respectively project retractably from a plurality of vane accommodating grooves provided in a rotor so as to be brought into sliding contact with a cam surface, low-pressure portions for sucking a hydraulic fluid from an outside and high-pressure portions for discharging the hydraulic fluid to the outside being adapted to be produced in pump chambers formed by the plurality of vanes between the cam surface and the rotor by the rotation of the rotor so as to supply the hydraulic fluid to a transmission of a vehicle, in order to serve as a hydraulic power source for the transmission of the vehicle;

an electric power-driven oil pump for assisting hydraulic pressure of the hydraulic fluid during an idling stop of the vehicle; and

a controller for controlling an operation of the electric power-driven oil pump,

wherein, during the idling stop of the vehicle, the hydraulic fluid is fed to the transmission by the operation of the electric power-driven oil pump to assist the hydraulic pressure, while the hydraulic fluid is fed with pressure to the vane accommodating grooves to press the vanes against the cam surface.

2. The oil pump system for a vehicle according to claim 1, wherein a communication oil passage is provided for allowing a discharge side of the electric power-driven oil pump and the vane accommodating grooves of the vane pump to communicate with each other, and a check valve is interposed in the communication oil passage, the check valve being opened when the hydraulic pressure of the hydraulic fluid delivered from the electric power-driven oil pump exceeds the hydraulic pressure of the hydraulic fluid in the vane accommodating grooves.

3. The oil pump system for a vehicle according to claim 1, wherein the electric power-driven oil pump has an internal gear pump and an electric motor for rotationally driving the internal gear pump, and a number of revolution of the electric motor is controlled by the controller.

4. The oil pump system for a vehicle according to claim 2, wherein the communication oil passage is configured as an oil passage on the discharge side of the electric power-driven pump, an annular hollow portion communicating with inside-diameter side end portions of the vane accommodating grooves, and a communication port connecting the annular hollow portion and the outside are communicated with each other, and

the annular hollow portion and the communication port are formed in an end plate for closing a space for accommodating the cam ring from one end side.

5. The oil pump system for a vehicle according to claim 3, wherein a number of revolution of the electric motor is controlled by the controller, and

a total discharge rate, which is a total of a discharge rate of the vane pump and a discharge rate of the electric power-driven oil pump, is set to a fixed rate in a rotation range of the engine at an idling speed or below.